pictures of size of bird just before slaughter?

This is our first time and we are only trying 2 meat birds to slaughter. I think the birds are cornish X's but the feed store only new them as being meat birds. I just want to know what is the ideal size to butcher before the meat gets too tough. My husband use to be a chef and I want this to be good for roasting. Both of them stagger when they walk as if they are gonna tip over. However, they still chase after bugs in the pen with the other 2 layers the same age. I think its close to the time but I want to get the most out of them as there are only 2. They are almost 8 weeks. Can anyone help? Any answers would be appreciated.

They'll definitely be bigger at 8 weeks than your layers, and most people slaughter meat chickens at 8 weeks. I have heard some say they take theirs to 12 weeks to get a really big bird. Beyond that, I haven't heard anyone going longer. I would assume as long as the chicken is under 6 months old, the meat should be tender. I think the main reason they are slaughtered at 8 weeks by the commercial growers is that they grow less efficiently after that, and it doesn't pay as much to grow them longer.

I'll bet the birds you bought are Cornish X. There is a Large Cornish X that is supposed to be some kind of giant mutant chicken. If the bird is large, white, and has a red comb and waddle, it's most likely a Cornish X.

Thank you for the replies. momoftwinsinwi that is exactly what my meat birds look like. Thank you so much and they look a little larger but they are not fully feathered. When they lift their wings I can see pink skin. Its great knowing having you all as a resource. I don't feel alone anymore and I love this site. Chickens are so addictive.
I was wondering if anyone has suggestions on the best way to slaughter for a roast chicken. I am more worried about removing the innards without breaking the bile and stuff. Do you just stick your hand in and pull everything out? Is it really that simple or do you need to take extra care not to break anything. Any suggestions would be helpful. I will be doing my sometime next week.

I just took my cornish X's to the processor at 10 weeks old. I could have maybe pushed it another week. They do have a hard time with the heat though. I got 6+ lb birds back from the processor. I kind of guess their weight before butchering to be around 8-10 lbs. They are really nice looking roasters.